1. Field of the Disclosure
The present disclosure relates generally to a fuser in an electrophotographic imaging device, and particularly to a heater of a belt fuser and controlling heat generation of the heater.
2. Description of the Related Art
In laser imaging devices, toner transferred to sheets of media using various electrophotographic techniques are then fused to the media by a fuser which applies heat and pressure to the toner. The heat and pressure are applied at a fusing nip formed in part by a backup roll. The fuser substantially permanently bonds the toner to the media as the media passes through the fuser nip. Toner fusing is the final step in the printing process of a laser imaging device.
There are a number of different fuser architectures, such as a hot roll fuser and a belt fuser. Belt fusers use a belt that is thinner than a hot roll in the hot roll fuser. The belt fuser thus has lower thermal mass to reduce warm-up time and energy usage for a faster and more efficient printing process.
However, the lower thermal mass of a belt fuser presents challenges when printing on narrow media. This is because the portions of the fuser nip that do not contact narrow media sheets quickly overheat, thereby potentially damaging some parts of the belt fuser. Belt fuser damage can be avoided by slowing the printing process, such as increasing the gap between successive pages in the media path, whenever narrow media is used. By slowing the printing process speed, the excess heat is allowed to conduct axially from the portion of the fuser nip through which the narrow media passes. In contrast, the hot roll fuser spreads excess heat axially even without slowing printing on the narrow media.
What is needed is a belt fuser that prints at roughly the same speeds as a hot roll fuser when printing on narrow media, while maintaining its fast warm-up and energy efficiency.